Electromagnetic sound reproducer



Dec. 31, 1929. R. L. BROWN 1,741,499

ELECTROMAGNET I C- SOUND REPRODUCER Filed Dec. 11;.1926 2 Sheets-Sheet l v 1 'INVENTORQ 4 jzfyazgvi lfrawzzj A"TORNEY..

Dec. 31, 1929.

R. 1.. BROWN ELECTROMAGNETIC SOUND REPRODUCER Filed 1926 2 Sheets-Sheet 2 IN V EN TOR.

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9 wherein Patented Dec. 31, 1929 [UNITED STATES I PATENT o fFicE.

BALIHL. BROWN, or nnwenx, NEW JERSEY, ASSIGNOR r :enennns LABORATORIES,

'INC., or'nnwancx, new JnnsnY, A CORPORATION on NEW JERSEY ELEGTRQM-AGNETIC sounn nnrnonuonn f .f .=l.-A 1i auoi1 filed Decemberll, 192s. seriaimliseesei My invention relates broadly to electro- ;m'agnet1c sound reproducers and more particularly to an electromagnetic sound repro- .ducer having a sound reproducing dia- ;,phragm of a free edge cone construction. I

:One of the objects of my invention is to provide an electromagnetic sound repioducer having a free edge sound reproducing dia-v phragmwhich is supported at its apex from a member which protrudes from the electromagnetic driver with means for steadying the cone shaped diaphragm at a plurality of points throughout'thearea of the cone shaped diaphragm. ,1 I I Anotherobject'ofmy invention is to pro vide-a free edge cone shaped sound reproducinm diaphragm construction in whicha plurality of flexible centering members are distributed throughout'the area ofnthe con- ZO cave side of the sound reproducing diaphragm for aligning the diaphragm with respectto the electromagnetic driver, the driver servingsto'support the diaphragm wholly from'the apex thereof.

provide a construction of centering devices which may be securedto the concave s de of the cone shaped-. sound reproducing dia-' phragm. at points distributed throughout the area; thereof, thecentering devices having a a flexible 'membrane thereon by which movementmay be freely imparted'to the cone shaped sound reproducing diaphragm while the diaphragm is, centered at all times .in a

selected position.

My invention will-be mote fully understood from the specification, hereinafter following by reference to the accompanying drawings .(Figure 1 a vertical crossrsectional view of the sound reproducer of my invention; Fig g' is;across-sectional viewtaken laterally through the electromagnetic sound reproducenof my invention; Fig. 3 is a detailed cross-sectional view showing the construction ofone of'the centering devices of my inven 'tion with the cone shaped sound reproducing diaphragm flexed to its extreme left hand position; and Fig. 4 is a detailed cross-sectional view of thecentering device flexed'to its extreme right hand position.

M. invention is. directed to that class of electromagnetic sound reproducers which em:

ploya free edge cone shaped sound reproducing diaphragm. The cone shaped diaphragm is supported from its apex to which vibrations are imparted from an electromagnetic driver. -'lhe -d-iaphragm is centered with respect to the electromagnetic driver by a plurality of centering devices positioned on the concave-side of the cone shaped sound reproducing diaphragm-and which connect with brace members extendmg from-thehousing 1 which encloses the' v many different directions. I Still another ob ect of my invention is to Referring to the drawings in more detail reference character 1 designates the base member for. the loudspeaker with an upwardly protruding member 2 carried thereby on which is supported the housing 3 for enclosing the electromagnetic driving mechanlsm. The housing 3 1s screw threaded to receive the rotatable plate member 4, which carmember e to a selected position. The shaft 7 is provided with an actuating control knob 8 which projects outside of the limits of the housing of the electromagnetic sound reproducer. member 10 secured adjacent the annular flange 11 of the sound reflector 12 is provided for supporting the rotatable shaft -7. Lug

members 14, 15 and 16'are formed on the housing 3 and to these lug members I connect brace members 17 18 and 19 which connect at their outer ends tothe centering devices 20, 21 and 22 which are secured to the concave A bearing 9 carried by depending I side ofthe sound reproducingdiaphragm 23. Each of the centering devices comprise circular members. I have illustrated the construction of the centering devices in detail in Figs. 3 and 4 as consisting of a cylindrical-portion 24 with radially: directed out-turned lug portions 25 which are secured to the rear of the sound reproducing diaphragm 23. The end ofthe cylindrical -portion 24 is turned in and permit free movement of the sound re producing diaphragm 23 under action of the electromagnetic driver in housing 3 through connecting rod 29 secured at its apex by -means of screw chuck device 30. The sound reproducing diaphragm 23 has'its free pe'- ripheral edge strengthened by a suitable bead 31. The beaded edge of the sound reproducing diaphragm extends Within the protection offered by the annular closure member 32 which connects at its periphery through bolt porting member, an actuating mechanism members 33 with the sound reflector 12. The sound reflector 12 is open at one side thereof as represented at 34, the opening being closed by means of ornamental grille 35. By this arrangement sound emanates from both the front and'rear of the cone shaped diaphragm 23 and is partially reflected by the reflecting surface formed by the .annular member 32 and by the reflecting surface 12, the conjoint action of which tends to substantially increase the volume of the reproduced sound.

The particularembodiment of my inven' tion as described herein has been found to be very practical in construction and desirable in operation although it should be understood that modifications may be made and that I intend no limitations upon my invention other than are imposed by the scope of the ap. pended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A. sound reproducer comprising a supporting member, an actuating mechanism car ried by said suppprting member, a free edge cone shaped sound reproducing diaphragm driven by said actuating mechanism and connections between said supporting member and three equi distant points on the concave side of said cone shaped sound reproducing diaphragm remote from the peripheral edge of the diaphragm in the direction of the apex for centering said diaphragm with respect to said actuating mechanism.

2. A sound reproducer comprising a-supcarried by said supporting member, a free edge cone shaped sound reproducing diaporting member, an actuating mechanism carried by said supporting member, a free edge cone shaped sound reproducing diaphragm driven by said actuating mechanism, and, means extending between said supportin member, and a. plurality'of points aroun the concave side of said cone shaped sound reproducing diaphragm remote from the edge of the diaphragm in the direction of the apex and flexibly connected 'with said diaphragm for centering said diaphragm with respect to said actuating mechanism.

4; A sound reproducer comprising .a supporting member, an actuating mechanism car ried by said supporting member, a free edge cone shaped sound reproducing diaphragm operated by said mechanism, a plurality of flexible connectors secured to the concave side of said conical-shaped sound reproducing diaphragm, in positions remote from the peripheral edge thereof, and connections between said connectors and said supporting member for centering saidsound reproducing diaphragm with respect to said actuating mechanism.

5. A sound reproducer comprising a supporting member, an actuating mechanism can ried by said supporting member, a free edge cone shaped sound reproducing diaphragm operated by said actuating mechanism, a plu- -rality of connecting members secured at a plurality of points about the concave surface of said sound reproducing diaphragm, each .of said connecting members including a re-- silient gasket device extending in a plane substantially parallel to the concave surface of the diaphragm, and a connection between the gasket devices of each of said members and said supporting member whereby said sound reproducing diaphragm may be centered with respect to said actuating mechanism.

6. A sound reproducer comprising a supporting member, an actuating mechanism carried by said supporting member, a free edge cone shaped sound reproducing diaphragm operated by said actuating mechanism,-a plurality of cylindrical members secured to the concave surface of said sound reproducing diaphragm, a flexible membrane closing one side of said cylindrical members, and connections between said flexible membrane and said supporting member for centering said diaphragm with respect to said actuating mechanism.

7. A sound reproducer comprising a super porting member,'an actuating mechanism carried by said supporting member, a free edge cone shaped sound reproducing diaphragm actuated by said actuating mechanism, means centering said diaphragm from points inside the concave surface thereof and remote from the peripheral edge of the cone and a sound reflector positioned adjacent the peripheral edge ofsaid sound reproducing diaphragm and centrally apertured adjacent the concave side of said sound reproducing diaphragm whereby sound is radiated from both sides of said sound reproducing diaphragm. '8."In a sound reproducer, a cone shaped sound reproducing diaphragm, anactuating driver, a housing enclosing said actuating driver, said driver having means for supporting said cone shaped sound reproducing diaphragm from the apex thereof and imparting vibratory motion thereto, and centering devices each comprising a flexible member secured in parallel spaced relation to one side of said diaphragm and a-flexible connection between each of said members and said hous- I n testimonywhereof I 'afiix my signature.

' RALPH L. BROWN. 

